Radium

Document v1 · published by Koskamo · updated 2026-10-04

Radium (Ra) is chemical element 88, an alkaline earth metal in group 2, period 7 (PubChem).

Atomic number: 88
Symbol: Ra
Group: 2
Period: 7
Atomic mass: 226.02541 u
Electron configuration: [Rn]7s2
Electronegativity (Pauling scale): 0.9
Atomic radius (van der Waals): 283 pm
Ionization energy: 5.279 eV
Oxidation states: +2
Standard state: Solid
Melting point: 973 K
Boiling point: 1413 K
Density: 5 g/cm³
Chemical group: Alkaline earth metal
Year discovered: 1898

Source and provenance

Original source: pubchem.ncbi.nlm.nih.gov
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: PubChem periodic table data (NIH/NLM, pubchem.ncbi.nlm.nih.gov/ptable); group and period from Jefferson Lab via PubChem

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Version history

Published by Koskamo2026-10-04
Version 1